#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>

extern char** environ;

int g_unval;
int g_val = 100;

int main(int argc, char *argv[], char *env[])
{
    const char *str = "helloworld";
    printf("code addr: %p\n", main);
    printf("init global addr: %p\n", &g_val);
    printf("uninit global addr: %p\n", &g_unval);
    static int test = 10;
    char *heap_mem = (char*)malloc(10);
    char *heap_mem1 = (char*)malloc(10);
    char *heap_mem2 = (char*)malloc(10);
    char *heap_mem3 = (char*)malloc(10);

    printf("heap addr: %p\n", heap_mem); //heap_mem(0), &heap_mem(1)
    printf("heap addr: %p\n", heap_mem1); //heap_mem(0), &heap_mem(1)
    printf("heap addr: %p\n", heap_mem2); //heap_mem(0), &heap_mem(1)
    printf("heap addr: %p\n", heap_mem3); //heap_mem(0), &heap_mem(1)

    printf("test static addr: %p\n", &test); //heap_mem(0), &heap_mem(1)
    printf("stack addr: %p\n", &heap_mem); //heap_mem(0), &heap_mem(1)
    printf("stack addr: %p\n", &heap_mem1); //heap_mem(0), &heap_mem(1)
    printf("stack addr: %p\n", &heap_mem2); //heap_mem(0), &heap_mem(1)
    printf("stack addr: %p\n", &heap_mem3); //heap_mem(0), &heap_mem(1)

    printf("read only string addr: %p\n", str);
    for(int i = 0 ;i < argc; i++)
    {
        printf("argv[%d]: %p\n", i, argv[i]);
    }
    for(int i = 0; env[i]; i++)
    {
        printf("env[%d]: %p\n", i, env[i]);
    }
    return 0;
}



//int main(int argc, char* argv[], char* env[])
//{
//    (void)argc;
//    (void)argv;
//    (void)env;

//    for(int i = 0; environ[i]; i++)
//    {
//        printf("environ[%d]->%s\n", i, environ[i]);
//    }
//

    //char* who = getenv("USER");
    //if(who == NULL) return 1;

    //if(strcmp(who, "cwf") == 0)
    //{
    //    printf("这是程序的正常执行逻辑\n");
    //}
    //else printf("only cwf！！\n");

    //char* value = getenv("PATH");
    //if(value == NULL) return 1;

    //printf("PATH->%s\n", value);


    //for(int i = 0; env[i]; i++)
    //{
    //    printf("env[%d]->%s\n", i, env[i]);
    //}


    //if(argc != 2)
    //{
    //    printf("Usage: %s [-a|-b|-c]\n", argv[0]);
    //    return 1;
    //}
    //char* arg = argv[1];
    //if(strcmp(arg, "-a") == 0)
    //    printf("这是功能1\n");
    //else if(strcmp(arg, "-b") == 0)
    //    printf("这是功能2\n");
    //else if(strcmp(arg, "-c") == 0)
    //    printf("这是功能3\n");

    //for(int i = 0; i < argc; i++)
    //{
    //    printf("argv[%d]: %s\n", i, argv[i]);
    //}

//    return 0;
//}
